Diaphragm valve



'7 Sheets-Sheet 1 INVENTOR.

ATTORNEY H. W. BOTELER DIAPHRAGM VALVE HENRY W. BOTELER BY@ f Sept. 10,1963 Filed Nov. 17. 1960 H. w. BQTELER DIAPHRAGM VALVE sept.l 10,1963,

7 sheetsfsheet 2 Filed No?. 17. 1960 FIGS INVEN TOR. vv. BOTELER HENRYATTORN EY Sept. -10, 1963 H. w. BOTELER 3,103,342

DIAPHRAGM VALVE Filed Nov. 17. 1960 '7 sheets-sheet s INVENTOR. HENRY W.BOTELER ZZM/@wy/ ATTORNEY sept.. 1o, 1963 Hw. BQTELER l3,103,341;

'r 'A DIAPrmAGM VALVE Filed Nov. 17. 1960 7 Sheets-Sheet 4 INVENTOR.HENRY VV. BOTELER F n G. 8 BY ATTOR NEY sept. 1o, 1963 H. w. BQTELER3,103,342

F1133 Nov. 17. 1930 .1 f v sheets-sheet s Y INVENTOR. HENRY vv. BQTELERATTORNEY Sept. 10, 1963 H. w. BOTELER DIAPHRAGM VALVE Filed Nov. 17.1960 1NVENToR. HE RY W BO LER BY ATTORNEY Sept. 10, 1963 H. w. BOTELER3,103,342

DIAPHRAGM VALVE Filed Nov. 17. 1960 7 Sheets-Sheet '7 INVENTOR. HENRYVV. BOTELER ATTORNEY United States Patent O Grinnell Corporation,Providence, RJ., a corporation of Delaware Filed Nov. 17, 1960, Ser. No.69,918 6 Claims. (Cl. 251-331) This application relates to improvementsin diaphragm valves. More particularly it has to do with diaphragmvalves of the kind which have diaphragrns with deeply bulged centralportions.

In general a diaphragm Valve has a body with a flow passagewaytherethrough which communicates with a` diaphragm opening on the side ofthe body between the ends thereof. A ilexible diaphragm has its marginclamped to the rim of this opening by a bonnet containing an actuatingmechanism which moves the central portion of the diaphragm into the flowpassageway to block the same and close the valve.

There are several arrangements in the diaphragm valve art for seatingthe `diaphragm against the surface of-the body to obtain a uid tightclosure. Perhapsthe best known involves a high weir which is in thenature of a web integral with the body and extending from the interiorsurface thereof opposite the opening a substantial distance toward saidopening. The surface of this web presented to the opening provides thediaphragm seat and is in the form of a concaved band with endsblendingsmoothly with the surface of a flange which is around the opening and towhich the diaphragm margin is clamped. The diaphragm is molded with itscentral portion slightlyv convexed or concaved and when pressed twardthe weir tits nicely thereagainst.

In these high-Weir valves the passageway openings at the ends of ithebody are conventionally circular, and as the passageway approaches theWeir from each of these ends its shape becomes oval but with across-sectional area not materially less than the cross-sectional areaof the circular openings. The proportions of the diaphragm opening, theWeir and diaphragm concavity are such that when the diaphragm is held inopen position the crosssectional area of the oval-shaped space betweenthe Weir and the diaphragm is again not materially less than theAcross-sectional area ofthe circular' openings. ner no undue restrictionto llow is produced.

In this above-described high-Weir valve construction In thismansubstantially half Iof Ethe cross-sectional area of the oval? shapedspace between the weir and the diaphragm inopen position is above thelevel of the diaphragm opening in the body and results from theconcavityof the diaphragm in this position. This portion of thecross-sectional area is relied upon to prevent flow restriction.

A relatively recent prior art improvement in this type of valve whichhas gone into widespread use has substantially eliminated the Weir byproviding a diaphragm in which the central portion is in the form of avery deep bulge capable of extending from the `diaphragm opening at thetop of the passageway all the way to the level of the bottom of .thecircular end openings. `In addition the passageway in this prior artimprovement is substantially cylindrical from one end of the valve tothe other, and a part of the cylindrical surface at the bottom ofv Ithepassageway opposite the opening is employed as a seating portion for thehemispherical end of the diaphragm cone. Above this seating portion itis necessary to provide some slope or taper in .the substantiallystraight sides of the bulge and a similar slope or taper on the bodyside walls (which extend to the diaphragm opening) to obtain a tightseal when the diaphragm is pressed against the body to close the valve.The greater the slope or taper (angle between the sides of the bulge)the better the seal,

fr* lee but also the larger the diaphragm opening which is adisadvantage because the pressure of the fluid in the valve acting overthe area of this opening produces ar force which opposes the closing ofthe valve. When this force is` large the actuating mechanism must bemade very strong, and in the case of hand operation considerablestrength or a large mechanical advantage is required.

In compromising vbetween large diaphragm bulge taper for good sealingand a small diaphragm opening in the body for easy operation ahighly-satisfactory design has been reached in the prior art, and thesevalves have enjoyed considerable popularity since their introduction.

Although lthe prior art no-weir valve above'referred to has had aseating with tapered side walls leading from the diaphragm openingsubstantially tangent to the cylindrical passageway, a part of whichforms the portion of the seating most remote from the diaphragm opening,there have been even more recent proposals in which this remote part ofthe seating has a configuration different than the arc of the passagewaycylinder. For example, this remote seating part may be a at floorsubstantially parallel to the plane of the diaphragm opening with smallradii where it joins the tapered side walls. Or this remote seating partmay follow some curve other than the arc of the cylinder, with .thiscurve blending smoothly into the side walls.

However, `all 'such arrangements have a' common feature which makes themparticularly attractive, namely, a seating which at its location mostremote from the diaphragm opening is a substantial distance therefromand which has steep side walls leading to the diaphragm opening. Thisarrangement provides the least abrupt change in direction of ilow. lhave observed, however, that in the prior art no-weir valves and themost recent proposals referred to, unlike the high Weir valves, thecross-sectional area at the seating is not merely about the same as thecross-sectional area at the ends of the valve but rather ismuchvgreater. The reason for this is that in the prior art no-'weirvalve the elimination of the weir and the taper in the sides of theseating provides a cross-sectional area below the diaphragm openingwhich is more than equal to the cross-sectional areaof the passageway atthe ends thereof, so that the additional- .cross-sectional area which isabove the diaphragm-opening and which results from the flexible sides ofthe central diaphragm bulge bowing upwardly provides a totalcross-sectional area at the seating much greater than'thecross-sectional area of the passageway ends.

Since the cross-sectional area of the opening at the seating in .theprior are no-weir valves is thus so much n greater than is required -toprevent restriction toflow it would seem that a diaphragm and seatingcombination of the same type but proportionally smaller could be used toobtain an opening atv-the seating which is substantially equal to the'cross-sectional area of the passageway at the ends of the valve."l'l'ler diiculty with this, however, is -that although there would bean adequate cross-sectional area at fthe seating, the passageway betweenthe ends of the valve and the diaphragm opening would have acrossseetional areaV which was becoming progressively less toward thediaphragm opening and which 'was less than the cross-sectional area atthe ends of the valve.

The present invention lhas todo with my discovery that for a valve witha passageway end'opening of a given size a diaphragm and seatingycombination of the no-weir type but proportionally smaller than 4thoseheretofore proposed can be -very successfully employed if the pas- Moreparticularly, this enlargement comprises curving centain walls of thepassageway youtwardly from a straight line drawn from the edge of theend opening to the seating (or to the diaphragm opening, as the case maybe) so that these walls curve rst outwardly and then inwardly again andform what are herein called recesses.

For the purpose of this invention valves of lthe 11o-Weir type may bedefined as those in which a sphere which is inserted through thediaphragm opening in the body and which is large eno-ugh to engage boththe straight, steeply sloping sides of the seating below this openinghas by far its greater portion below the plane of the surface arounddiaphragm opening to which the diaphragm margin is clamped.

The advantage of a valve in accordance with this invention is that the'diaphragm opening which determines the effective area against which theline pressure acts to resist valve closure can be substantially reducedin comparison to the no-weir valves of the same size heretofore proposedand at the same time the pressure drop through the valve when the valveis in open position `can be kept surprisingly low.

One of the advantages ofthe recent prior art improvements previouslydescribed is the substantially straight configuration of the bottom(when the body is oriented in space with the diaphragm opening presentedupwardly) of the ow passageway from one end of the valve to the other.This enables complete draining of any horizontal pipe line section inwhich such a valve is located and is a desirable feature. By far themost preferred embodiment of the present invention achieves this samestraight yconfiguration of the bottom of the ow passageway through thevalve by having the diaphragm opening set far enough down below the toplevel of the passageway openings at the ends off the body Ifor the endot the central diaphragm portion to reach to the bottom level of thepassageway openings at the ends `of the body. The top level of 4thepassageway -then slopes downward from the ends of the body to thelowered level of the diaphragm opening, and the pockets of thisinvention are preferably formed at ythe sides of the passageway althoughthey may .be formed at the top of the passageway or at bot-h the sidesand top.

Another embodiment or' this invention involves the location ofthediaphragm opening at the top level of the passageway openings at theends of the body. Here again the opening is relatively smaller than inthe recent prior art improvements with the result that in closedposition the diaphragm does not extend to the bottom level of thepassageway openings at the ends of the body. Accordingly, from the endsof the body the bottom level of the passageway sweeps upto the seatingat the center `of the body.

If it is desired to make this slope very gentle, beginning at thepassageway end openings, a restriction to flow will result like thatcaused by the downwardly sloping top level of the passageway in therst-mentioned embodiment. In such cases recesses at the sides or at thetop ofthe passageway between the diaphragm opening and the passagewayends would substantially compensate for this restriction. On the otherhand, if it is satisfactory to make this slope somewhat more abrupt andhave it begin closer to the seat the compensation for restriction willbe in the form of bottom recesses between the diaphragm opening and thepassageway ends. In addition various combinations of these constructionsare possible with side, bottom and top recesses.

Accordingly it is an object of Ithe present invention to provide animproved diaphragm valve which is eicient in operation and inexpensiveto manufacture.

Another object of the invention is to provide an improved diaphragrnvalve of the type having a diaphragm with a deeply bulged centralportion which, in valve closed position, extends into the body from thediaphragm opening therein a distance substantially less than thediameter of the iiow passageway at the ends of the valve, whereincertain walls ot the passageway between the end opening thereof and theseating or `diaphragm opening curve outwardly from a straight line drawnIfrom the edge of the end opening to the seating `or to the ydiaphragmopening and thereby form smo-oth recesses in the passageway walls.

Another object of the invention is to provide an improved diaphragmvalve of the type described in which the recesses are so located thatacross section of the passageway taken parallel to the plane of one endopening and taken between such end opening and the seating shows across-sectional passageway area having at least one portion outside theperpendicular projection of such end opening on the plane of such crosssection.

Another object of the invention is to provide an improved diaphragmvalve of the type described in which the diaphragm opening in the bodyis set substantially below the top level of the flow passageway at theends of the valve.

Another object of the invention is to provide an improved diaphragmvalve of the type described in which the diaphnagm opening is setsubstantially below this top level of the ow passageway, in which thecentral portion of the diaphragm extends to the bottom level of thepassageway at the ends of the valve and in which the bottom surface ofthe passageway forms a substantially straight line from one end of thevalve to the other.

Another object of the invention is to provide an improved diaphragmvalve of the type described in which the diaphragm opening is located atthe top level of the flow passageway lat the ends ,of the valve.

Another object of the present invention is to provide an improveddiaphragm valve of the type described in which the choisis-,sectional:area portions outside the projection are at the Sides of thepassageway, or at the bottorn of the passageway, or :at the rop of thepassageway, or any combination of these.

Another object of the invention is :to provide an improved diaphragmvalve of the type described in which. the passageway end openings aresubstantially circular and in which the central diaphragm portion issxibstantially hemispherical with a diameter substantially smaller thanthe diameter of the passageway end openings.

Other objects will appear hereinafter.

The best modes in which I have contemplated applying the principles ofmy improvements are shown in the accompanying drawings, but ythese areto be deemed merely illustrative for it is intended that the: patentshall cover by suitable expression inthe appended claims whatever ;ofpatentable novelty exists in the invention disclosed.

In the drawings:

FIGURE 1 is a cross-sectioned iside elevation view of one embodiment ofthe present invention showing the valve in open position;

FIGURE 2 is a View like FIG. l, but omitting parts of lthe `actuatingmechanism and showing the valve in closed position;

FIGURE 3 is a View taken on line 3 3 of FIG. l;

FIGURE 4 is a View taken on line 4-li of FIG. l;

FIGURE 5 is a top plan view partly sectioned yof the body shown in the'embodiment of FIGS. l-4;

FIGURES 6, 9 and 12 yare side elevation views like the lbody in FIG. lbut showing three other embodiments of the invention;

FIGURES 7, l0 and 13 are crosssection views taken on lines 7-7, itl-10and 1.3--13 of FIGS. 6, 9 and l2, respectively;

FIGURES 8, ll and 14 are top plan views, partly sectioned, of the bodiesof FIGS. 6r, 9 tand 1&2, respectively;

FIGURES l5 and 16 are views like FIG. 4 but sho ing other shapes for thediaphragm seating.

Referring now to FIGS. 1-5 of the drawings, these show a preferredembodimentor present invention employing a valve body which has a pairof substan- -tially circular end openings 12 surrounded by anges 14 withwhich the valve is secured in a pipe line 16. As shown best in FIGS. land 2 a flow passageway 18 connects these openings 12, and the bottom 20of this passageway is essentially straight `liront one Opening 12 to theother. However, from the top ot each of the openings 12 the wall 22 ofthe passageway slopes downwardly -to the diaphragm opening 24 in the topof the'body.

As best shown in FIG. 4 the shape of the openings 12 is circular buttheoross-sectional shape .of the flow passageway inwardly from'these endopenings 12 loses its circular configuration primarily by the downwardsloping passageway top walls 22 and by the appearance of shallowrecesses 26 (FIGS. 4 and 5) which are located in this embodiment at thesides of the passageway. The existence of these recesses as hereindelinedi-s established by the fact that a straight line 27 dnawn fromthe edge of the opening 12 to the seating 28 along the flow passagewayis'spaced inwardly from the wall of .the flow passageway. This is a newstructural arrangement in diaphragm valves of the :type whichthisinvention is concerned, because as far :as I am aware the passagewaywalls in all such previously proposed `diaphragm valves of this typehave been dened by such straight lines as 27.

Resist-ance to llow in diaphragm valves is not solely a function of the4amount of restriction 1in cross-sectional area which may Iappear fromplace to'place.' In other Words by merely making sure that thecross-sectional area along the valve body is everywhere equal to thecross-sectional area of the openings at theends of the body does notgive `the valve a resistance to flow eq=ual to that :of 'a straightpiece .of pipe. Turbulence caused by the changing shape of the newpassageway and the changing direction of the line of ow within thepassageway are also very important in determining the amount ofresistance to flow in the valve as a whole.

I have discovered, however, that the provision of the recesses 26between the seating 28 (or the edges 30 of the diaphragm opening as theca-se may be) andthe passageway ends 12 greatly improves the ll-ow.Since the recesses26 cannot be formed on the bottomof the passageway inthe embodiment of FIGS. l to 5 without upsetting its straight llineconfiguration it remains for the recesses to be located at the sides ortop of the passageway, and FIGURE 4 illustrates these recesses 26 at thesides by showing that the surface ofthe sidesof the passageway areradially outside of the line 27.

Referring to FIG. 3, this illustrates particularly well that thediaphragm 43 employed is 'of the deeply-bulged type.` This type may berecognized bythe fact that a sphere 36 (shown bydot-'dash lines in FIG.4) inserted in the diaphragm opening 24 and lange enough to engage thesteeply sloped straight portions 28a ofthe'4 diaphragm seating 28 liessubstantially entirely on one-side of the plane 40 ot the flange 42which is around the diaphragm opening 24 and to which the marginalportion 43a of the diaphragm 43 is t-o be clamped. In the embodiment ofFIGS. l-S the central portion 28h of the Iseating is the arc of a circleto which the straight side seating portions 28a are tangent so that asphere like 36 also engages this central seating portion ZSb. A somewhatlarger sphere 36a is also shown in FIG. 4 demonstrating'fthat thisembodiment is well within vthe proportions required for the presentinvention because even this larger sphere 36a is substantially entirelybelow the plane 40. l

In accord-ance with the present invention the-spheres 36 and 36a aresmaller in diameter than the circle defining the passageway end openings12.

As a result of the above-described Istructural relationships the body inFIGS. 1-5 has a pair of smallsidewebs 44 on which the seating 28 isfor-med. To avoid abrupt changes in the direction of flow within thepassageway the surfaces of the passageway are blended smoothly 6 fromthe ends 12 into the recesses 26 and then out of these recesses to theseating 28.

' As in prior aat diaphragm valves having diaphragms of the deepcone-shaped type, the valve of FIGS. l-5 has the marginal portion 43a ofthe diaphragm 43'clamped around the diaphragm opening 24 by the lowerhanged end 46 of a bonnet 48 which houses the mechanism 49 for advancingthe diaphragm toward its seat and for withdrawing the diaphragm from itsseat to open the Valve.

FIGURE 3 illustrates that the cross-sectional area of the flowpassageway at the seating is more than equal to the cross-sectional areaatv the end openings 12. 'I'his is true despite the fact that theAdiaphragm opening 24 is proportional-ly smaller than in prior art'no-Weir valves and is due in large measure to the .annular cavity 50created by the rolled diaphragm skirt portion 4317 and located above theplane 40 of the diaphragm opening.

As previously described, the diaphragm opening 24 in this embodiment ofFIGS. 1 5 is set below the top level of the passageway at the ends ofthe body. This is made clear by the fact that a plane 51 parallel to theIplane 40 and tangent to the top of the end opening-s 12 is spaced thevalve to the seating 6%. If it is desired to have the' slope of thisbottom level as gradual as possible, as shown in FIG; l6, it remains forthe recesses 62 to. be located again atthe sides of the passageway. Asin the previous embodiment, the recesses are .those areas radiallyoutward from straight lines 63 drawn along the how passageway :from theend openings 58 to the seating 60 (see FIG. 8).

In this embodiment of FIGS. 6-8 the location of the diaphragm opening 42and the seating 60'is more particularly defined by reference to a plane64 which includes the diaphragm clamping surface around the diaphragmopening, another plane 64a parallel to plane 64 and including theunderside 52a of the diaphragm opening, another plane 65 also parallelto plane 64 -and including the part of the central seat portion 60awhich is most remote from the plane 64, and still another plane 66 also;parallel to plane 64 and tangent to the end openings 58 on the side ofthe plane 65 .remote from the plane 64. In accordance with thisembodiment of the invention planes 65 and 66 are spaced substantiallyapart. In this embodiment the 4recesses 62 extend well into the areaunder the diaphragm openi-ng S2. This has the yadvantage that anyrestriction to iow caused by the edge of the diaphragm opening 52passing over the flow passageway is compensated for by't'he portions 62of the recesses in this region.

FIGURES 9-ll are like FIGS. 6-8 and illust-rate that if it is desired tohave the sidewalls 67 of the passageway surface as straight las possiblebetween the end openings 68 andthe seating 69, the recesses 70 can belocated at the bottom 71 of the passageway. That these recesses arepre-sent' is once more illustrated by the presence of the areas 70radially outside the straight lines 72 shown in FIGS. 9 and 10. Y

It will be understood that the :recesses need not be entirely on thesides of the passageway or entirely at the bottom of the passageway butif desired may extend to both regions.

FIGURES 12-14 show another embodiment like that ofyFVIGS. 6-8 exceptthat the recesses 74 (radially outside the straightY lines 76) are -atthe top of the passageway rather than lat the sides or bottom.

FIGURES l5 and 16 are views like FIG. 4 but showing that the seatingportion 78a remote from the diaphragm opening 80 need not be a part of acircle as in the earlier embodiments. More particularly, in FIG. 15 thestraight sloping side portions 'i817 of the seating extending from thesides of the diaphragm opening 80 join a remote central seating portion'78a which is essentially straight, small radii SZ being provided at thejuncture'with the side seating portions 7819.

In FIG. 16 the construction and numbers are similar except that from thesloping straight side portions 7817 the seating begins to curve at S4 toa rounded apex 86.

In both FIG. 15 and FIG. 16 the diaphragm would have a central portionmolded to iit the shape of the seating.

In each of these seating shapes the characteristic feature which isnecessary for the present invention is the relatively large distancefrom the diaphragm opening to the most remote part of the seatingcompared to the size of the diaphragm opening. It is this proportionwhich provides large cross-sectional ilow area above the diaphragmopening when the diaphragm is in open position (for example, the cavity5G in FIG. 3). I have found that this feature is present when a sphere36 or 36a (see FIG. 4) inserted in the diaphragm opening and largeenough to engage both steeply sloped straight side seating portions 28ulies substantially entirely below the plane 40 of the clamping ilange 42which is around the diaphragm opening 24tand to which the diaphragm isclamped.

In FIGS. and 16 such a sphere is indicated by the numeral 88.

Whereas the existence of recesses or pockets in the walls of the flowpassageway in accordance with this invention results from the Wallsbeing curved outwardly from a straight line such as the line 27 in FIG.5, by far the most effective recesses are those which are also radiallyoutside an imaginary cylinder including the circular end openings andextending into the passageway. This is illustrated, for example, by thefact that in FIGS. 5, 8 and 9 there are portions 26a, 62a and 70u,respectively, of the pockets which are outside imaginary cylinders 9'2perpendicular to the end openings. In FIG. 12 line 76 is alreadyperpendicular to the plane of the end opening.

I claim:

l. A diaphragm valve comprising:

(I) a hollow rigid body having:

(A) a pair Iof end openings which:

(1) are substantially circular,

(2) have substantially equal diameters, (B) a circular diaphragm openingwhich:

(1) is on one side of said body,

(2) is intermediate said end openings,

(3) is surrounded by a flange surface in a flat plane,

(C) an interior surface which:

(l) extends between said openings,

(2) forms with said openings interior edges, (D) a diaphragm seatingband which:

( 1) is located on said body interior surface,

(Z) is located opposite said diaphragm openlng (3) has a central portionspaced from said at plane by a distance less than said diameters,

(4) has a pair of corresponding spacedapart side portions which:

(a) extend into said body from opposite sides of said diaphragm opening,

(b) are substantially straight,

(c) slope steeply inwardly,

(d) engage a sphere-which: (i) is inserted through said diaphragmopening, (ii) lies substantially entirely on the same side of said flatplane Where said seating portions are located,

(II) a ilexible diaphragm which:

(A) covers said diaphragm opening,

(B) has a central bulged portion which:

(1) engages said seating in the closed valve position,

(2) is bowed to the opposite side of said diaphragm opening in the openvalve position,

(III) said interior body surface and said diaphragm defining apassageway which:

(A) extends through the body between said end openings,

(B) has a portion which:

(1) has one end formed by the interior edge of one of said end openings,

(2) has another end formed by the interior edge of said diaphragmopening and by the seating band,

(3) has at least some walls which curve out- Wardly from straight lineswhich:

(a) are drawn along said passageway portion,

(b) are drawn between the ends of said portion,

(C) has a cross sectional area at the seating in the open valve positionwhich is at least as great as the cross sectionalarea of each of the endopenings,

(D) has each cross sectional area along the portion at least as great asthe cross sectional area of each of the end openings.

2. A diaphragm valve as set forth in claim 1 in which every point 0n thesaid interior edge of said diaphragm opening is spaced substantially:

(A) toward said central seating band portion,

(B) from another plane which:

(1) is tangent to the interior edges of both said end openings,

(2) is located on the side of said end openings v remote from saidcentral seating band portion.

3. A diaphragm valve as set forth in claim 2, wherein the said interiorbody surface which is most remote from said other plane is substantiallystraight.

4. A diaphragm valve as set forth in claim l in which said centralportion of said seating band is spaced substantially:

(I) toward said diaphragm opening,

(II) from another plane which:

(A) is tangent to the said interior edges of both said end openings,

(B) is located on the side of said end openings remote from saiddiaphragm opening.

5. A diaphragm valve according to claim 4, wherein the said interiorbody surface opposite said diaphragm opening slopes gradually from saidother plane to the central seating portion.

6. A diaphragm valve :as set forth in claim 1 in which:

(I) said end openings lie in spaced apart parallel first and secondplanes,

(II) the perpendicular projection of one end opening on the plane of theother end opening substantially coincides with said other end opening,

(III) a cross section of said passageway portion taken in a third planeparallel to said first and second planes` provides an area of saidpassageway which has at least one substantial portion you-tside aperpendicular projection of either of said end openings on said thirdplane.

References Cited in the le of this patent UNITED STATES PATENTS2,716,0117 Linker Aug. 23, 1955

1. A DIAPHRAGM VALVE COMPRISING: (I) A HOLLOW RIGID BODY HAVING: (A) APAIR OF END OPENINGS WHICH: (1) ARE SUBSTANTIALLY CIRCULAR, (2) HAVESUBSTANTIALLY EQUAL DIAMETERS, (B) A CIRCULAR DIAPHRAGM OPENING WHICH:(1) IS ON ONE SIDE OF SAID BODY, (2) IS INTERMEDIATE SAID END OPENINGS,(3) IS SURROUNDED BY A FLANGE SURFACE IN A FLAT PLANE, (C) AN INTERIORSURFACE WHICH: (1) EXTENDS BETWEEN SAID OPENINGS, (2) FORMS WITH SAIDOPENINGS INTERIOR EDGES (D) A DIAPHRAGM SEATING BAND WHICH: (1) ISLOCATED ON SAID BODY INTERIOR SURFACE, (2) IS LOCATED OPPOSITE SAIDDIAPHRAGM OPENING, (3) HAS A CENTRAL PORTION SPACED FROM SAID FLAT PLANEBY A DISTANCE LESS THAN SAID DIAMETERS, (4) HAS A PAIR OF CORRESPONDINGSPACEDAPART SIDE PORTIONS WHICH: (A) EXTEND INTO SAID BODY FROM OPPOSITESIDES OF SAID DIAPHRAGM OPENING, (B) ARE SUBSTANTIALLY STRAIGHT, (C)SLOPE STEEPLY INWARDLY, (D) ENGAGE A SPHERE WHICH: (I) IS INSERTEDTHROUGH SAID DIAPHRAGM OPENING, (II) LIES SUBSTANTIALLY ENTIRELY ON THESAME SIDE OF SAID FLAT PLANE WHERE SAID SEATING PORTIONS ARE LOCATED,